Study sheds new light on why the effectiveness of a popular HIV prevention method varies in women

March 1, 2018, University of Manitoba

Why do some women get HIV infection, even though they are using tenofovir gel for prophylaxis?

A new study by scientists at the Centre for the AIDS Programme in Research in South Africa (CAPRISA), published in Nature Medicine this week, shows that genital inflammation significantly reduces the effectiveness of in preventing HIV infection in women. These findings indicate that both genital inflammation and adherence need to be addressed to improve the effectiveness of topical pre-exposure prophylaxis strategies for HIV prevention in women.

The researchers measured small proteins, known as cytokines, in the vagina. Raised cytokines levels in the vagina indicate the presence of inflammatory immune responses, even in the absence of clinical symptoms. In this study, HIV infection rates and cytokine levels as a marker of genital inflammation were studied longitudinally in 774 women over 2.5 years.

Lead authors of the study, Lyle McKinnon, an adjunct professor of medical microbiology at the University of Manitoba, and Lenine Liebenberg, University of KwaZulu-Natal, found that women with genital inflammation were at higher risk of subsequently contracting HIV compared to women without inflammation.

"Reducing inflammation of the in women may augment the HIV prevention in women," McKinnon says.

The study highlights the major role of genital inflammation in HIV risk and in modifying the efficacy of HIV prevention strategies. Current and future attempts to improve topical PrEP efficacy would benefit from knowing the causes of inflammation, and developing new strategies to treat genital inflammation, co-author Liebenberg notes.

One such effort is currently underway at the University of Manitoba, where a study is being led by Keith Fowke to use the anti-inflammatory, Acetylsalicylic acid (known commonly as aspirin), to reduce inflammatory responses in the female genital tract.

In the meantime, Liebenberg and McKinnon's study shows that tenofovir gel provided 57 per cent protection against HIV acquisition in women who had no evidence of vaginal inflammation but provided no protection in women with genital , even if they used the gel consistently.

"This study gives us an important clue to enhance HIV prevention in women. It is not only adherence-related behaviours, but also biological processes in the vaginal that need to be addressed to prevent HIV and enhance the effectiveness of topical PrEP," said Professor Salim Abdool Karim, Director of CAPRISA and CAPRISA Professor of Global Health at Columbia University.

Explore further: Bacterial communities of female genital tract have impact on inflammation, HIV risk

Related Stories

Bacterial communities of female genital tract have impact on inflammation, HIV risk

May 19, 2015
A team led by researchers from Massachusetts General Hospital (MGH) and the Ragon Institute of MGH, MIT and Harvard has found that the most common bacterial community in the genital tract among healthy South Africa women ...

Study: Site of first chlamydia exposure makes big difference

January 26, 2018
Exposing the gut to chlamydia protects against subsequent infection in the genital tract and other tissues, researchers from UT Health San Antonio discovered. Chlamydia is the nation's most common sexually transmitted disease ...

New evidence on why young women in South Africa are at high risk of HIV infection

July 18, 2016
Evidence by the Centre for the AIDS Programme of Research in South Africa (CAPRISA) consortium of South African and North American researchers will be presented on July 18 at the International AIDS 2016 Conference in Durban, ...

Inflammation in testes could explain link between obesity and reduced fertility

February 7, 2018
A new study sheds light on how obesity may contribute to male infertility. Published in open-access journal Frontiers in Physiology, the study reports that obese men have increased levels of inflammatory markers in their ...

Certain species of vaginal bacteria can increase a woman's susceptibility to HIV

January 10, 2017
Specific bacteria living in the human vagina may play a previously unrecognized role in the sexual transmission of HIV. Ragon Institute researchers, working with young, healthy, South African women, found that individuals ...

Prevalence of oral HPV infection higher for U.S. men

October 17, 2017
(HealthDay)—Oral human papillomavirus (HPV) infection and high-risk oral HPV infection are more common among men than women, according to a study published online Oct. 16 in the Annals of Internal Medicine.

Recommended for you

Researchers discover influenza virus doesn't replicate equally in all cells

September 19, 2018
The seasonal flu is caused by different subtypes of Influenza A virus and typically leads to the death of half a million people each year. In order to better understand this virus and how it spreads, University of Minnesota ...

Flu season forecasts could be more accurate with access to health care companies' data

September 19, 2018
In an era when for-profit companies collect a wealth of data about us, new research from The University of Texas at Austin shows that data collected by health care companies could—if made available to researchers and public ...

Drugs that stop mosquitoes catching malaria could help eradicate the disease

September 18, 2018
Researchers have identified compounds that could prevent malaria parasites from being able to infect mosquitoes, halting the spread of disease.

Vaccine opt-outs dropped slightly when California added more hurdles

September 18, 2018
In response to spiking rates of parents opting their children out of vaccinations that are required to enroll in school—and just before a huge outbreak of measles at Disneyland in 2014—California passed AB-2109. The law ...

New evidence of a preventative therapy for gout

September 17, 2018
Among patients with cardiovascular disease, it's a common complaint: a sudden, piercing pain, stiffness or tenderness in a joint that lasts for days at a time with all signs pointing to a gout attack. Gout and cardiovascular ...

"Atypical" virus discovered to be driver of certain kidney diseases

September 14, 2018
An international research team led by Wolfgang Weninger has discovered a previously unknown virus that acts as a "driver" for certain kidney diseases (interstitial nephropathy). This "atypical" virus, which the scientists ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.